1. Technical Field
The present invention relates to a video management apparatus and a method for event recording using the same capable of reducing loss in video recording based on an occurrence of events.
2. Related Art
As known in the art, network cameras transmit video that is captured in a compressed form to a video management system (VMS) via a network because of the constraint of network bandwidth. In the field of video compression, video consists of an I-frame (Intra frame) followed by a number of P-frames (Predicted frames). The I-frame is used as a requisite reference or key data in video decoding. I-frames have more data than other frames and thus may have an effect on designing network bandwidth and storage space of the video management system depending on how often the I-frames are transmitted.
Meanwhile, the video management system may rather employ event recording methods than real-time recording methods, as shown in, for example, the Korean Patent Laid-Open Publication No. 2013-0124757 (published on Nov. 15, 2013).
An event recording method requires a certain time to get video after requesting it from video sources such as network cameras, which results in that a portion of the video to be recorded may be lost for the certain time.
In order to solve the above mentioned problem, the video management system utilizes pre-event recording methods.
A pre-event recording method refers to an approach to continue a pseudo-recording even in a situation where no event occurs, and pseudo-recorded information may be used as actual recorded information upon the occurrence of events, which may prevent the loss of the recorded material in the event recording method. In the pre-event recording method, the time for the pseudo-recording may be set by a user or as a default value to the video management system.
In the pre-event recording method, the longer the time for the pseudo recording is, the more the storage space of the video management system may be wasted. Therefore, it is common to set the time for the pseudo recording time as short as possible.
For a short pseudo recording time, however, any key frame, which is requisite in a video decoding, i.e., any I-frame may not be available during the short pseudo recording time, which makes the video recording abnormal.